Road surfaces are typically made from asphalt, which is a mixture of a binder, such as bitumen, and aggregate. Many attempts have been made to provide a luminescent road surface that emits light, thereby reducing the need for street lights and potentially increasing safety for road users. WO 92/18573 discloses a binder for asphalt comprising a hydrocarbon component that is fluorescent in ultraviolet light. WO 93/11302 discloses a process wherein phosphorescent plastics or resins are added to conventional bituminous paving. WO 95/10663 discloses a process wherein fluorescent material is mixed with cement and sand, and formed into granules, and the granules can be incorporated into a road surface.
The present inventors have sought to provide road surfaces that exhibit luminescence.